A scroll compressor is a certain type of compressor that is used to compress refrigerant for such applications as refrigeration, air conditioning, industrial cooling and freezer applications, and/or other applications where compressed fluid may be used. Such prior scroll compressors are known, for example, as exemplified in U.S. Pat. No. 6,398,530 to Hasemann; U.S. Pat. No. 6,814,551, to Kammhoff et al.; U.S. Pat. No. 6,960,070 to Kammhoff et al.; and U.S. Pat. No. 7,112,046 to Kammhoff et al., all of which are assigned to a Bitzer entity closely related to the present assignee. As the present disclosure pertains to improvements that can be implemented in these or other scroll compressor designs, the entire disclosures of U.S. Pat. Nos. 6,398,530; 7,112,046; 6,814,551; and 6,960,070 are hereby incorporated by reference in their entireties.
As is exemplified by these patents, scroll compressors assemblies conventionally include an outer housing having a scroll compressor contained therein. A scroll compressor includes first and second scroll compressor members. A first compressor member is typically arranged stationary and fixed in the outer housing. A second scroll compressor member is movable relative to the first scroll compressor member in order to compress refrigerant between respective scroll ribs which rise above the respective bases and engage in one another. Conventionally the movable scroll compressor member is driven about an orbital path about a central axis for the purposes of compressing refrigerant. An appropriate drive unit, typically an electric motor, is provided usually within the same housing to drive the movable scroll member.
In some scroll compressors, it is known to have axial restraint, whereby the fixed scroll member has a limited range of movement. This can be desirable due to thermal expansion when the temperature of the orbiting scroll and fixed scroll increases causing these components to expand. Examples of an apparatus to control such restraint are shown in U.S. Pat. No. 5,407,335, issued to Caillat et al., the entire disclosure of which is hereby incorporated by reference.
In a scroll compressor, there is typically some amount of load that is induced in the axial direction of the crankshaft. For a vertical scroll compressor, this load is a combination of the mass of the rotating components as well as any electrically induced load caused by intentional or unintentional axial misalignment of the motor stator and motor rotor. These loads are commonly transmitted between the rotating crankshaft and a stationary housing a thrust surface. The thrust surface may be designed into the stationary component but such surface tends to wear away and surface preparation must be given careful consideration which adds costs to the compressor. It is also known to use a thrust washer, but to prevent unwanted movement, such thrust washer is fixed in place with various ways including the use of fastener(s), adhesive or tabs formed into the circumference of the washer. Such methods add cost to the compressor.
The present disclosure is directed towards improvements over the state of the art as it relates to the above-described features and other features of scroll compressors.